Organic photosensitive optoelectronic devices with transparent electrodes

Abstract

An organic photosensitive optoelectronic device optimized to enhance desired characteristics such as external quantum efficiency is described. The photosensitive optoelectronic device has at least two transparent electrodes and one or more organic photoconductive layers disposed between the transparent electrodes. In other embodiments photosensitive optoelectronic devices with multilayer photoconductive structures and photosensitive optoelectronic devices with a reflective layer are disclosed.

1. A device, comprising:
 a plurality of organic photosensitive subcells stacked in a superposed relationship over a substrate, each subcell comprising a heterojunction between two organic semiconductor materials; 
 a first organic photosensitive subcell of the plurality of organic photosensitive subcells having a first absorption characteristic; 
 a second organic photosensitive subcell of the plurality of organic photosensitive subcells having a second absorption characteristic, wherein the second absorption characteristic is different from the first absorption characteristic; and 
 a conductive layer disposed between and in a superposed relationship with the first organic photosensitive subcell and the second organic photosensitive subcell, wherein the conductive layer is an electrode or charge transfer layer, and wherein the conductive layer is transparent or semitransparent, 
 wherein the device is optimized for use as a photovoltaic cell. 
 
     
     
       2. The device of  claim 1 , wherein the conductive layer has a thickness of about 1000 to 4000 angstroms. 
     
     
       3. The device of  claim 2 , wherein the conductive layer includes indium tin oxide. 
     
     
       4. The device of  claim 1 , wherein the conductive layer is a part of the first organic subcell, and the conductive layer is a part of the second organic subcell. 
     
     
       5. The device of  claim 1 , wherein the first and second subcells are adjacent, and the conductive layer is not a part of the first organic subcell. 
     
     
       6. The device of  claim 1 , wherein the conductive layer is an electrode. 
     
     
       7. The device of  claim 1 , wherein the conductive layer is a charge transfer layer. 
     
     
       8. The device of  claim 1 , wherein the first organic photosensitive subcell has an absorption maxima that is different from the absorption maxima of the second organic photosensitive subcell. 
     
     
       9. The device of  claim 1 , wherein the first and second subcells are electrically connected in series. 
     
     
       10. The device of  claim 1 , wherein the first and second subcells are electrically connected in parallel. 
     
     
       11. The device of  claim 1 , wherein the conductive layer permits at least 50% of the ambient electromagnetic radiation to be transmitted through the layer. 
     
     
       12. The device of  claim 1 , wherein a material composition of the first organic photosensitive subcell is different from a material composition of the second organic photosensitive subcell. 
     
     
       13. A device, comprising:
 a first organic photosensitive subcell having a first spectral sensitivity, stacked in a superposed relationship with a substrate, the first organic photosensitive subcell comprising a first heterojunction between two organic semiconductor materials; 
 a second organic photosensitive subcell, stacked in a superposed relationship with the first organic photosensitive subcell over the substrate, the second organic photosensitive subcell having a second spectral sensitivity that is different from the first spectral sensitivity and comprising a second heterojunction between two organic semiconductor materials; and 
 a conductive layer disposed between and in a superposed relationship with the first organic photosensitive subcell and the second organic photosensitive subcell, wherein the conductive layer is an electrode or charge transfer layer, and wherein the conductive layer is transparent or semitransparent, 
 wherein the device is optimized for use as a photovoltaic cell. 
 
     
     
       14. The device of  claim 13 , wherein the conductive layer has a thickness of about 1000 to 4000 angstroms. 
     
     
       15. The device of  claim 14 , wherein the conductive layer includes indium tin oxide. 
     
     
       16. The device of  claim 13 , wherein the conductive layer is a part of the first organic subcell, and the conductive layer is a part of the second organic subcell. 
     
     
       17. The device of  claim 13 , wherein the first and second subcells are adjacent, and the conductive layer is not a part of the first organic subcell. 
     
     
       18. The device of  claim 13 , wherein the conductive layer is an electrode. 
     
     
       19. The device of  claim 13 , wherein the conductive layer is a charge transfer layer. 
     
     
       20. The device of  claim 13 , wherein the first subcell has an absorption maxima that is different from the absorption maxima of the second subcell. 
     
     
       21. The device of  claim 13 , wherein the first and second subcells are electrically connected in series. 
     
     
       22. The device of  claim 13 , wherein the first and second subcells are electrically connected in parallel. 
     
     
       23. The device of  claim 13 , wherein the conductive layer permits at least 50% of the ambient electromagnetic radiation to be transmitted through the layer. 
     
     
       24. The device of  claim 13 , wherein a material composition of the first organic photosensitive subcell is different from a material composition of the second organic photosensitive subcell. 
     
     
       25. A device, comprising:
 a plurality of organic photosensitive subcells stacked in a superposed relationship over a substrate, each subcell comprising a heterojunction between two organic semiconductor materials; 
 wherein the plurality of organic photosensitive subcells is comprised of subcells having dissimilar absorption characteristics; 
 wherein two adjacent subcells are connected by a charge transfer layer that is isolated from external circuits, wherein the charge transfer layer is transparent or semitransparent; and 
 wherein the device is optimized for use as a photovoltaic cell. 
 
     
     
       26. The device of  claim 25 , wherein every pair of adjacent subcells are connected by a charge transfer layer that is not directly connected electrically to an external circuit. 
     
     
       27. The device of  claim 25 , wherein the charge transfer layer comprises a low resistance metal substitute material that has been deposited by sputtering. 
     
     
       28. The device of  claim 27 , wherein the charge transfer layer further comprises a metallic layer. 
     
     
       29. The device of  claim 25 , wherein the charge transfer layer has a thickness of about 1000 to 4000 angstroms. 
     
     
       30. The device of  claim 29 , wherein the charge transfer layer includes indium tin oxide. 
     
     
       31. The device of  claim 25 , wherein the charge transfer layer permits at least 50% of the ambient electromagnetic radiation to be transmitted through the layer.